View Code of Problem 73

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		int N=scanner.nextInt();
		int sum=1;
		for(int i=1;i<N;i++) {
			sum=(sum+1)*2;
		}
		System.out.println(sum);
	}
}